Is there any doubt? The top of the road is the safest, generally. The bottom side doesn't sound too fun, and left and right sides require me to know what country I'm in (yeah like I'd be able to figure that out).

I consider pretty much everywhere on the road. I ride a motorcycle and for each car lane there are 3 bike lanes. So I like the left lane out of the three but I am always ready to use the 4th lane(the white line on the side of the road) when traffic gets bad.

I also ride a motorbike and I have found the center lane
to be the best during peak traffic. Theres nothing like
going straight up the middle of a huge queue of tin-tops
at the lights. I feel so sorry for car drivers :)

The top of the road is the "side" where I want to be, because not only it is the safest, but it is also the direction my philosophy asks me to take: up, up, up, because I want to improve myself all the time and become a Saint..